The proposal under consideration focuses on the non-DNA-binding CBF(beta) subunit of the core binding protein CBF, a heterodimeric transcription factor. CBF(beta) is thought to allosterically regulate CBF(alpha), the DNA-binding subunit. The PI proposes to employ site directed mutagenesis to define the interaction surface in CBF(beta) to confirm the three dimensional structural information provided by NMR spectroscopy (Specific Aim 1). The NMR component of the research will be done in collaboration with Dr. John Bushweller at Dartmouth College. The investigator will also examine the expression of Cbfb during embryogenesis, determine the concentration of CBF-beta in hematopoietic cells (Specific Aim 2), and identify and biochemically characterize sequences in CBF-beta required for hematopoiesis (Specific Aim 3). This proposal is being submitted as an Interactive Research Project Grant in conjunction with J. Peter Gergen, who studies the Drosophila homologues of the CBF-beta protein. The two proposals describe a combined use of biochemical and genetic approaches to study the function of the CBF-beta protein in both the Drosophila and mouse systems.